Beamforming Training Method and Apparatus

ABSTRACT

A beamforming training method and apparatus relating to the field of beamforming training technologies, where the beamforming training method includes sending, by a first device, first indication information to a second device, where the first indication information indicates the second device not to perform an initiator sector sweep (ISS), sending, by the first device, a sector sweep frame of a responder sector sweep (RSS) to the second device, and receiving, by the first device, feedback information obtained by the second device during the RSS. Hence, beamforming training flexibility can be improved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2017/109120 filed on Nov. 2, 2017, which claims priority toChinese Patent Application No. 201610956679.0 filed on Nov. 3, 2016. Thedisclosures of the aforementioned applications are hereby incorporatedby reference in their entireties.

TECHNICAL FIELD

This application relates to the field of beamforming trainingtechnologies, and in particular, to a beamforming training method andapparatus.

BACKGROUND

A millimeter-wave band is a high-frequency communication band, and apropagation loss is very large. Therefore, a gain of a transmit antennaand/or a gain of a receive antenna are/is usually used to compensate fora path loss. The transmit antenna and the receive antenna usually form adirectional beam using an antenna array having a large-scale antennaarray element or a group of switchable beam antennas, and a transmitbeam and a receive beam that are aligned between the transmit antennaand the receive antenna are formed through beamforming training in orderto close a communication link or expand coverage. Therefore, a procedureof simulating beamforming training is designed in some millimeter wavetechnical standards. For example, the Institute of Electrical andElectronics Engineers (IEEE) 802.11ad and 802.11ay standards for a 60gigahertz (GHz) band include a sector level sweep (SLS) phase and a BeamRefinement Protocol (BRP) phase. The SLS phase is an inevitable phasefor initial establishment of a beam link. In this phase, at least a besttransmit sector of each communication party can be determined. In theBRP phase, based on the best sector obtained in the SLS phase,beamforming training is further performed to obtain best antennaconfigurations and best beam link gains of the transmit and receiveparties.

In the 802.11ad standard, SLS beamforming training includes a maximum offour parts, an initiator sector sweep (ISS) used for initiator beamtraining, a responder sector sweep (RSS) used for responder beamtraining, a sector sweep (also referred to as SSW) feedback(SSW-Feedback) step, and an SSW acknowledgment (SSW-Ack) step. Whenbeamforming training is performed according to the standard, a deviceserving as a beam training initiator and a device serving as a beamtraining responder form an SLS training group through informationexchange. SLS training between the initiator device and the responderdevice in the SLS training group always includes two parts an ISS and anRSS.

The beamforming training always includes two parts the ISS and the RSS,and is suitable for one-to-one training of a pair of devices. However,the SLS phase training is inflexible, which is not beneficial toexpanding beamforming training to more devices in real time and reducingtotal duration of beamforming training between a plurality of devices.

SUMMARY

Embodiments of the present disclosure provide a beamforming trainingmethod and apparatus in order to improve beamforming trainingflexibility.

According to a first aspect, an embodiment of the present disclosureprovides a beamforming training method, including sending, by a firstdevice, first indication information to a second device, where the firstindication information indicates the second device not to perform anRSS, sending, by the first device, a sector sweep frame of an ISS to thesecond device, and receiving, by the first device, feedback informationobtained by the second device during the ISS.

In the other approaches solution, beamforming training always includestwo parts, an ISS and an RSS, causing SLS training inflexibility. In thesolution in this embodiment of the present disclosure, the first devicesends, to the second device, the first indication information used toindicate the second device not to perform the RSS training. Therefore,after the first device sends the sector sweep frame of the ISS to thesecond device, the second device performs ISS training based on thereceived sector sweep frame and no longer performs the responder RSStraining. It can be learned that, in the solution in this embodiment ofthe present disclosure, the ISS and the RSS may be separately performedsuch that beamforming training flexibility can be improved.

In the solution in this embodiment of the present disclosure, the firstdevice may directly send the first indication information to the seconddevice using a straight-through link. Alternatively, the first devicefirst includes the first indication information in beamforming trainingrequest information and sends the first indication information to awireless access point (AP)/personal basic service set control point(PCP), and then the AP/PCP sends the first indication information to thesecond device when allocating a channel transmission resource, to bespecific, forwards the first indication information to the second deviceby including the first indication information in scheduling informationof the AP/PCP.

In a possible design, before sending, by the first device, a sectorsweep frame of an ISS to the second device, the method further includesreceiving, by the first device, a sector sweep frame of firstbeamforming training of the second device, where an address of the firstdevice does not match a receive address of the sector sweep frame of thefirst beamforming training, and determining, by the first device, sectorselection information or signal-to-noise ratio (SNR) information of thefirst beamforming training based on the received sector sweep frame ofthe second device.

In the other approaches solution, only a device in a beamformingtraining group, namely, only a device whose address falls within areceive address range of a sector sweep frame sent by a beamformingtraining initiator (corresponding to the second device), can receive thesector sweep frame sent by the second device. However, in the solutionin this embodiment of the present disclosure, the first device whoseaddress does not match the receive address of the sector sweep frame ofthe first beamforming training may also receive the sector sweep frameof the first beamforming training to perform beamforming training suchthat a device outside the beamforming training group can also performbeamforming training, thereby increasing beamforming trainingflexibility.

Optionally, the second device is not limited to a beamforming traininginitiator, or may be a beamforming training responder in a beamformingtraining group.

Optionally, the first beamforming training and the ISS training of thefirst device in the foregoing design may be separately performed interms of time, and may be combined into a complete beamforming trainingprocess.

In a possible design, the first beamforming training includes an ISSand/or the RSS of the second device.

In a possible design, the determining, by the first device, sectorselection information or SNR information of the first beamformingtraining based on the received sector sweep frame of the second deviceincludes determining, by the first device, the sector selectioninformation of the second device based on the sector sweep frame of thesecond device when the first beamforming training includes a transmitsector sweep (TXSS) of the second device.

In a possible design, determining, by the first device, sector selectioninformation or SNR information of the first beamforming training basedon the received sector sweep frame of the second device includesdetermining, by the first device, whether a quantity of sector sweepframes sent by the second device is greater than or equal to a quantityof receive sectors that the first device needs to sweep when the firstbeamforming training includes a receive sector sweep (RXSS) of thesecond device, and if the quantity of sector sweep frames sent by thesecond device is greater than or equal to the quantity of receivesectors that the first device needs to sweep, determining, by the firstdevice, SNR information of a transmit sector of the first device basedon the received sector sweep frame of the second device.

In a possible design, the method further includes, if the quantity ofsector sweep frames sent by the second device is less than the quantityof receive sectors to be swept by the first device, sending, by thefirst device, second indication information to the second device, wherethe second indication information is used to indicate RXSS lengthinformation of a responder RXSS of the second device after the ISS ofthe first device.

In this embodiment of the present disclosure, when the quantity ofsector sweep frames sent by the second device is less than the quantityof receive sectors to be swept by the first device, the second deviceperforms RXSS training after the ISS training of the first device basedon the second indication information sent by the first device such thatthe second device performs RSS training based on an actual requirement,beamforming training flexibility is improved, and total beamformingtraining time is reduced.

In a possible design, the first indication information is indicationinformation used to indicate the second device not to perform aresponder TXSS and/or a responder RXSS after the ISS of the firstdevice.

In a possible design, the first indication information is included in asector sweep SSW frame or a short SSW frame of the ISS of the firstdevice, or included in a grant frame or a service period (SP) requestframe.

In a possible design, the first indication information is the sectorselection information or the SNR information.

In an implementation of this embodiment of the present disclosure, thefirst device sends the first indication information and the sector sweepframe of the ISS to the second device without considering a timesequence. That is, in a possible implementation, the first indicationinformation and the sector sweep frame of the ISS are separately sent.For example, the first indication information is included in the grantframe or the SP request (also referred to as SPR) frame. In anotherpossible implementation, the first indication information and the sectorsweep frame of the ISS may be sent together. For example, the firstindication information is included in the sector sweep SSW frame or theshort SSW frame of the ISS.

In terms of content of the first indication information, the firstindication information may be the sector selection information or theSNR information, and the first indication information implicitlyindicates that the RSS is no longer performed.

In a possible design, before sending, by the first device, the firstindication information, the method further includes determining, by thefirst device, that when the ISS of the first device ends, the sectorselection information is within a preset beam link maintenance time.

In a possible design, after receiving, by the first device, feedbackinformation obtained by the second device during the ISS, the methodfurther includes sending, by the first device, a sector sweep frame ofsecond beamforming training to the second device, and receiving, by thefirst device, sector selection information or SNR information, based onthe second beamforming training, of the second device.

In an implementation solution of the other approaches, beamformingtraining always includes two parts, an ISS and an RSS. In thisimplementation, only a sending link and a receiving link of the firstdevice may be trained, thereby improving beamforming trainingflexibility.

In a possible design, the ISS of the first device is an initiator TXSS,and the second beamforming training is an initiator RXSS, or the ISS ofthe first device is an initiator RXSS, and the second beamformingtraining is an initiator TXSS.

According to a second aspect, an embodiment of the present disclosureprovides a beamforming training method, including sending, by a firstdevice, beamforming training request information to a second device,where the beamforming training request information includes at least onetype of training phase information, channel number information, channelbandwidth information, channel transmission mode information, andinformation about a quantity of spatial flows of a training sequence,receiving, by the first device, configuration information fed back bythe second device based on the beamforming training request information,and performing, by the first device, beamforming training based on theconfiguration information.

In an existing beamforming training method, when requesting a channelresource, a beamforming training initiator does not differentiatechannel characteristics. In the solution in this embodiment of thepresent disclosure, when requesting or negotiating a beamformingtraining resource, a beamforming training initiator (corresponding tothe first device) includes one or more types of the training phaseinformation, the channel number information, the channel bandwidthinformation, the channel transmission mode information, and theinformation about a quantity of spatial flows of a training sequence inthe beamforming training request information in order to request thesecond device to allocate or negotiate to determine a channel with acharacteristic specified in the request information for beamformingtraining.

An implementation of this embodiment of the present disclosure may beapplied to a process in which an initiator in a beamforming traininggroup requests a resource, or may be applied to a process in which adevice outside the beamforming training group requests a resource as aninitiator.

In a possible design, the beamforming training request information isincluded in an SP request frame, a grant frame, or a grantacknowledgment frame.

In a possible design, the training phase information is used to indicatean SLS phase or a BRP phase.

In this implementation, the training phase information in thebeamforming training request information indicates the SLS phase or theBRP phase such that the second device allocates a channel resourcecorresponding to a corresponding training phase.

In a possible design, the channel number information is used to indicatewhether a channel with a specified number is requested for beamformingtraining.

In this implementation, the channel number information is used toindicate whether the channel with the specified number is requested suchthat the second device allocates the channel with the specified numberfor beamforming training.

In a possible design, when the channel number information indicates thatthe channel with the specified number is requested, or when the trainingphase information indicates the BRP phase, the channel bandwidthinformation is used to indicate one or more channel numbers, and whenthe channel number information indicates that the channel with thespecified number is not requested, or when the training phaseinformation indicates the SLS phase, the channel bandwidth informationis used to indicate a channel bandwidth.

In a possible design, the channel transmission mode information is usedto indicate whether a beamforming training sequence uses a channelaggregation mode or a channel bonding mode.

In a possible design, when the training phase information indicates theBRP phase, the information about a quantity of spatial flows of atraining sequence is used to indicate a quantity of transmit spatialflows of a training field.

According to a third aspect, an embodiment of the present disclosureprovides a beamforming training method, including receiving, by a seconddevice, beamforming training request information sent by a first device,where the beamforming training request information includes at least onetype of training phase information, channel number information, channelbandwidth information, channel transmission mode information, andinformation about a quantity of spatial flows of a training sequence,and allocating, by the second device to the first device based on thebeamforming training request information, a channel used for beamformingtraining.

In an existing beamforming training method, when requesting a channelresource, a beamforming training initiator does not differentiatechannel characteristics. Correspondingly, when allocating a channelaccording to a request of the first device, the second device does notdifferentiate channel resource characteristics. In the solution in thisembodiment of the present disclosure, when requesting or negotiating abeamforming training resource, a beamforming training initiator(corresponding to the first device) includes one or more types of thetraining phase information, the channel number information, the channelbandwidth information, the channel transmission mode information, andthe information about a quantity of spatial flows of a training sequencein the beamforming training request information. Therefore, whenallocating a channel resource to the first device or negotiating withthe first device to determine a channel resource, the second deviceallocates a channel resource based on a channel characteristic specifiedin the beamforming training request information.

In a possible design, the beamforming training request informationincludes the training phase information and/or the channel numberinformation, and further includes the channel bandwidth information,when the training phase information indicates an SLS phase, and/or thechannel number information in the beamforming training requestinformation indicates that a channel with a specified number is notrequested, the channel bandwidth information is used to indicate achannel bandwidth, and allocating, by the second device to the firstdevice based on the beamforming training request information, a channelused for beamforming training includes allocating, by the second deviceto the first device, a channel whose channel bandwidth is less than orequal to the channel bandwidth indicated by the channel bandwidthinformation.

In a possible design, the beamforming training request informationincludes the training phase information and/or the channel numberinformation, and further includes the channel bandwidth information,when the training phase information indicates a BRP phase, and/or thechannel number information in the beamforming training requestinformation indicates that a channel with a specified number isrequested, the channel bandwidth information is used to indicate one ormore channel numbers, and allocating, by the second device to the firstdevice based on the beamforming training request information, a channelused for beamforming training includes allocating, by the second deviceto the first device, at least one channel whose channel number isindicated by the channel bandwidth information.

In a possible design, the beamforming training request informationincludes the channel bandwidth information, and the channel bandwidthinformation indicates zero, and the allocating, by the second device tothe first device based on the beamforming training request information,a channel used for beamforming training includes allocating, by thesecond device, any single channel to the first device.

In a possible design, the beamforming training request informationincludes the channel transmission mode information, and the channeltransmission mode information is used to indicate whether a beamformingtraining sequence uses a channel aggregation mode or a channel bondingmode, and the allocating, by the second device to the first device basedon the beamforming training request information, a channel used forbeamforming training includes allocating, by the second device to thefirst device, a channel whose channel mode is the same as a channel modeindicated by the channel transmission mode information.

In a possible design, the beamforming training request informationincludes the information about a quantity of spatial flows of a trainingsequence and the training phase information, and when the training phaseinformation indicates the BRP phase, the information about a quantity ofspatial flows of a training sequence is used to indicate a quantity oftransmit spatial flows of a training field, and allocating, by thesecond device to the first device based on the beamforming trainingrequest information, a channel used for beamforming training includesallocating, by the second device to the first device, a channel for BRPtraining and with a quantity of spatial flows the same as the quantityof spatial flows indicated by the information about a quantity ofspatial flows of a training sequence.

According to a fourth aspect, an embodiment of the present disclosureprovides a beamforming training apparatus, where the apparatus isdeployed on a first device, and the apparatus has a function ofimplementing behavior of the first device in the beamforming trainingmethod design of the first aspect. The function may be implemented byhardware, or may be implemented by hardware executing correspondingsoftware. The hardware or the software includes one or more modulescorresponding to the function. The module may be software and/orhardware.

In a possible design, the beamforming training apparatus includes asending unit and a receiving unit, the sending unit is configured tosend first indication information to a second device, where the firstindication information indicates the second device not to perform anRSS, and send a sector sweep frame of an ISS to the second device, andthe receiving unit is configured to receive feedback informationobtained by the second device during the ISS.

In a possible design, before the sending unit sends the sector sweepframe of the ISS to the second device, the receiving unit is furtherconfigured to receive a sector sweep frame of first beamforming trainingof the second device, where an address of the first device does notmatch a receive address of the sector sweep frame of the firstbeamforming training, and the apparatus further includes a firstprocessing unit configured to determine sector selection information orSNR information of the first beamforming training based on the receivedsector sweep frame of the second device.

In a possible design, the first beamforming training includes an ISSand/or the RSS of the second device.

In a possible design, that the first processing unit determines sectorselection information or SNR information of the first beamformingtraining based on the received sector sweep frame of the second deviceincludes determining the sector selection information of the seconddevice based on the sector sweep frame of the second device when thefirst beamforming training includes a TXSS of the second device.

In a possible design, that the first processing unit determines sectorselection information or SNR information of the first beamformingtraining based on the received sector sweep frame of the second deviceincludes determining whether a quantity of sector sweep frames sent bythe second device is greater than or equal to a quantity of receivesectors that the first device needs to sweep when the first beamformingtraining includes an RXSS of the second device, and if the quantity ofsector sweep frames sent by the second device is greater than or equalto the quantity of receive sectors that the first device needs to sweep,determining SNR information of a transmit sector of the first devicebased on the received sector sweep frame of the second device.

In a possible design, if the quantity of sector sweep frames sent by thesecond device is less than the quantity of receive sectors to be sweptby the first device, the sending unit is further configured to sendsecond indication information to the second device, where the secondindication information is used to indicate RXSS length information of aresponder RXSS of the second device after the ISS of the first device.

In a possible design, the first indication information is indicationinformation used to indicate the second device not to perform aresponder TXSS and/or a responder RXSS after the ISS of the firstdevice.

In a possible design, the first indication information is included in asector sweep SSW frame or a short SSW frame of the ISS of the firstdevice, or included in a grant frame or an SP request frame.

In a possible design, the first indication information is the sectorselection information or the SNR information.

In a possible design, the apparatus further includes a second processingunit configured to, before the sending unit sends the first indicationinformation, determine that when the ISS of the first device ends, thesector selection information is within a preset beam link maintenancetime.

In a possible design, after the receiving unit receives the feedbackinformation obtained by the second device during the ISS, the sendingunit is further configured to send a sector sweep frame of the secondbeamforming training to the second device, and the receiving unit isfurther configured to receive sector selection information or SNRinformation, based on the second beamforming training, of the seconddevice.

In a possible design, the ISS of the first device is an initiator TXSS,and the second beamforming training is an initiator RXSS, or the ISS ofthe first device is an initiator RXSS, and the second beamformingtraining is an initiator TXSS.

In another possible design, the beamforming training apparatus includesa receiver, a transmitter, and a processor, the receiver is configuredto implement a function of the receiving unit in the embodiment of thefourth aspect, the transmitter is configured to implement a function ofthe sending unit in the embodiment of the fourth aspect, and theprocessor is configured to implement functions of the first processingunit and the second processing unit in the embodiment of the fourthaspect.

According to a fifth aspect, an embodiment of the present disclosureprovides a beamforming training apparatus, where the apparatus isdeployed on a first device, and the apparatus has a function ofimplementing behavior of the first device in the beamforming trainingmethod design of the second aspect. The function may be implemented byhardware, or may be implemented by hardware by executing correspondingsoftware. The hardware or the software includes one or more modulescorresponding to the function. The module may be software and/orhardware.

In a possible design, the beamforming training apparatus includes asending unit, a receiving unit, and a beamforming training unit, thesending unit is configured to send beamforming training requestinformation to a second device, where the beamforming training requestinformation includes at least one type of the following informationtraining phase information, channel number information, channelbandwidth information, channel transmission mode information, andinformation about a quantity of spatial flows of a training sequence,the receiving unit is configured to receive configuration informationfed back by the second device based on the beamforming training requestinformation, and the beamforming training unit is configured to performbeamforming training based on the configuration information.

In a possible design, the beamforming training request information isincluded in an SP request frame, a grant frame, or a grantacknowledgment frame.

In a possible design, the training phase information is used to indicatean SLS phase or a BRP phase.

In a possible design, the channel number information is used to indicatewhether a channel with a specified number is requested for beamformingtraining.

In a possible design, when the channel number information indicates thatthe channel with the specified number is requested, or when the trainingphase information indicates the BRP phase, the channel bandwidthinformation is used to indicate one or more channel numbers, and whenthe channel number information indicates that the channel with thespecified number is not requested, or when the training phaseinformation indicates the SLS phase, the channel bandwidth informationis used to indicate a channel bandwidth.

In a possible design, the channel transmission mode information is usedto indicate whether a beamforming training sequence uses a channelaggregation mode or a channel bonding mode.

In a possible design, when the training phase information indicates theBRP phase, the information about a quantity of spatial flows of atraining sequence is used to indicate a quantity of transmit spatialflows of a training field.

In another possible design, the beamforming training apparatus includesa receiver, a transmitter, and a processor, the receiver is configuredto implement a function of the receiving unit in the embodiment of thefifth aspect, the transmitter is configured to implement a function ofthe sending unit in the embodiment of the fifth aspect, and theprocessor is configured to implement a function of the beamformingtraining unit in the embodiment of the fifth aspect.

According to a sixth aspect, an embodiment of the present disclosureprovides a beamforming training apparatus, where the apparatus isdeployed on a second device, and the apparatus has a function ofimplementing behavior of the second device in the beamforming trainingmethod design of the third aspect. The function may be implemented byhardware, or may be implemented by hardware by executing correspondingsoftware. The hardware or the software includes one or more modulescorresponding to the function. The module may be software and/orhardware.

In a possible design, the beamforming training apparatus includes areceiving unit and an allocation unit, the receiving unit is configuredto receive beamforming training request information sent by a firstdevice, where the beamforming training request information includes atleast one type of the following information training phase information,channel number information, channel bandwidth information, channeltransmission mode information, and information about a quantity ofspatial flows of a training sequence, and the allocation unit isconfigured to allocate, to the first device based on the beamformingtraining request information, a channel used for beamforming training.

In a possible design, the beamforming training request informationincludes the training phase information and/or the channel numberinformation, and further includes the channel bandwidth information,when the training phase information indicates an SLS phase, and/or thechannel number information in the beamforming training requestinformation indicates that a channel with a specified number is notrequested, the channel bandwidth information is used to indicate achannel bandwidth, and that the allocation unit allocates, to the firstdevice based on the beamforming training request information, a channelused for beamforming training includes allocating, to the first device,a channel whose channel bandwidth is less than or equal to the channelbandwidth indicated by the channel bandwidth information.

In a possible design, the beamforming training request informationincludes the training phase information and/or the channel numberinformation, and further includes the channel bandwidth information,when the training phase information indicates a BRP phase, and/or thechannel number information in the beamforming training requestinformation indicates that a channel with a specified number isrequested, the channel bandwidth information is used to indicate one ormore channel numbers, and that the allocation unit allocates, to thefirst device based on the beamforming training request information, achannel used for beamforming training includes allocating, to the firstdevice, at least one channel whose channel number is indicated by thechannel bandwidth information.

In a possible design, the beamforming training request informationincludes the channel bandwidth information, and the channel bandwidthinformation indicates zero, and allocating, by the second device to thefirst device based on the beamforming training request information, achannel used for beamforming training includes allocating, by the seconddevice, any single channel to the first device.

In a possible design, the beamforming training request informationincludes the channel transmission mode information, and the channeltransmission mode information is used to indicate whether a beamformingtraining sequence uses a channel aggregation mode or a channel bondingmode, and that the allocation unit allocates, to the first device basedon the beamforming training request information, a channel used forbeamforming training includes allocating, to the first device, a channelwhose channel mode is the same as a channel mode indicated by thechannel transmission mode information.

In a possible design, the beamforming training request informationincludes the information about a quantity of spatial flows of a trainingsequence and the training phase information, and when the training phaseinformation indicates the BRP phase, the information about a quantity ofspatial flows of a training sequence is used to indicate a quantity oftransmit spatial flows of a training field, and that the allocation unitallocates, to the first device based on the beamforming training requestinformation, a channel used for beamforming training includesallocating, to the first device, a channel for BRP training and with aquantity of spatial flows the same as the quantity of spatial flowsindicated by the information about a quantity of spatial flows of atraining sequence.

In another possible design, the beamforming training apparatus includesa receiver, a transmitter, and a processor, the receiver is configuredto implement a function of the receiving unit in the embodiment of thesixth aspect, the transmitter is configured to implement a function ofthe sending unit in the embodiment of the sixth aspect, and theprocessor is configured to implement a function of the allocation unitin the embodiment of the sixth aspect.

According to a seventh aspect, an embodiment of the present disclosureprovides a computer storage medium configured to store a computersoftware instruction used by the beamforming training apparatusaccording to the fourth aspect. The computer software instructionincludes a program designed for performing the first aspect.

According to an eighth aspect, an embodiment of the present disclosureprovides a computer storage medium configured to store a computersoftware instruction used by the beamforming training apparatusaccording to the fifth aspect. The computer software instructionincludes a program designed for performing the second aspect.

According to a ninth aspect, an embodiment of the present disclosureprovides a computer storage medium configured to store a computersoftware instruction used by the beamforming training apparatusaccording to the sixth aspect.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flowchart of a beamforming training method according toEmbodiment 1 of the present disclosure;

FIG. 2 is a schematic diagram of a possible application scenario of thepresent disclosure;

FIG. 3 is a schematic diagram of another possible application scenariobased on FIG. 2;

FIG. 4 is a flowchart in which a hidden device participates inbeamforming training as a responder;

FIG. 5 is a flowchart in which a hidden device participates inbeamforming training as an initiator;

FIG. 6 is a flowchart in which a hidden device uses an initiator in abeamforming training group as a target station (STA) to participate inbeamforming training;

FIG. 7 is a flowchart in which a hidden device uses an initiator and aresponder in a beamforming training group as target STAs to participatein beamforming training;

FIG. 8 is another flowchart in which a hidden device participates inbeamforming training as an initiator;

FIG. 9 is a flowchart of a beamforming training method according toEmbodiment 3 of the present disclosure;

FIG. 10 is a schematic diagram of antenna sectors of a STA and a hiddendevice;

FIG. 11 is a flowchart of a beamforming training method according toEmbodiment 4 of the present disclosure;

FIG. 12 is a flowchart of a beamforming training method according toEmbodiment 5 of the present disclosure;

FIG. 13 is a schematic diagram of a channel aggregation transmissionmode;

FIG. 14 is a schematic diagram of a channel bonding transmission mode;

FIG. 15 is a schematic diagram of a channel aggregation transmissionmode in a BRP phase;

FIG. 16 is a schematic diagram of a channel bonding transmission mode ina BRP phase;

FIG. 17 is a schematic diagram of a channel bonding transmission mode ina contention based access period (CBAP);

FIG. 18 is a schematic diagram of a channel aggregation transmissionmode in a CBAP;

FIG. 19 is a schematic structural diagram of a beamforming trainingapparatus according to an embodiment of the present disclosure;

FIG. 20 is a schematic structural diagram of another beamformingtraining apparatus according to an embodiment of the present disclosure;and

FIG. 21 is a schematic structural diagram of yet another beamformingtraining apparatus according to an embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

In a summary of an existing beamforming training method, beamformingtraining always includes two parts, an ISS and an RSS. Consequently,beamforming training is inflexible. To improve beamforming trainingflexibility, the embodiments of the present disclosure provide abeamforming training method. In the method, an ISS and an RSS ofbeamforming training may be performed separately.

FIG. 1 is a flowchart of a beamforming training method according toEmbodiment 1 of the present disclosure. As shown in FIG. 1, the methodincludes the following processing steps.

Step S101: A first device sends first indication information to a seconddevice, where the first indication information indicates the seconddevice not to perform an RSS.

Step S102: The first device sends a sector sweep frame of an ISS to thesecond device.

Step S103: The first device receives feedback information obtained bythe second device during the ISS.

In the solution in this embodiment of the present disclosure, a sequencefor performing step S101 and step S102 is not limited, and step S101 andstep S102 may be simultaneously performed. For example, the sector sweepframe of the ISS sent by the first device to the second device includesthe first indication information.

Further, the first device may directly send the first indicationinformation to the second device using a straight-through link.Alternatively, the first device first includes the first indicationinformation in beamforming training request information and sends thebeamforming training request information to a wireless AP/PCP, and thenthe AP/PCP sends the beamforming training request information to thesecond device when allocating a channel transmission resource, to bespecific, forwards the first indication information to the second deviceby including the first indication information in scheduling informationof the AP/PCP.

In the solution in this embodiment of the present disclosure, the firstdevice sends, to the second device, the first indication informationused to indicate the second device not to perform the RSS. Therefore,after receiving the sector sweep frame of the ISS sent by the firstdevice, the second device performs corresponding beamforming trainingbased on the sector sweep frame of the ISS, while performing the RSStraining is not necessary, thereby implementing separation between theISS beamforming training and the RSS beamforming training, and improvingbeamforming training flexibility.

With reference to the solution of Embodiment 1, in another possiblesolution of the present disclosure, the first device may also performpartial beamforming training as a beamforming training responder.Optionally, the first device independently performs partial beamformingtraining as a device outside a beamforming training group. The firstdevice may independently perform partial beamforming training as thedevice outside the beamforming training group before the first devicesends the sector sweep frame of the ISS to the second device or afterthe first device sends the sector sweep frame of the ISS to the seconddevice.

In an optional implementation solution, before the first device sendsthe sector sweep frame of the ISS to the second device, the first devicereceives a sector sweep frame of first beamforming training of thesecond device. An address of the first device does not match a receiveaddress of the sector sweep frame of the first beamforming training. Thefirst device determines sector selection information or SNR informationof the first beamforming training based on the received sector sweepframe of the second device.

In the solution in this embodiment of the present disclosure, the firstbeamforming training may be an ISS and/or the RSS of the second device.Further, because the address of the first device does not match thereceive address of the sector sweep frame of the first beamformingtraining, it may be considered that the first device is a device outsidea corresponding beamforming training group, and the second device may bean initiator or a responder in the beamforming training group.

In the other approaches solution, only a device in a beamformingtraining group, namely, only a device whose address falls within areceive address range of a sector sweep frame sent by a beamformingtraining initiator (corresponding to the second device), can receive thesector sweep frame sent by the second device. However, in the solutionin this embodiment of the present disclosure, the first device whoseaddress does not match the receive address of the sector sweep frame ofthe first beamforming training may also receive the sector sweep frameof the first beamforming training to perform beamforming training suchthat a device outside the beamforming training group can also performbeamforming training, thereby increasing beamforming trainingflexibility.

To describe this embodiment of the present disclosure in detail, thefollowing describes beamforming training of the present disclosure withreference to a specific scenario and one beamforming training instancein the specific scenario. It may be understood that the followingspecific scenario and the beamforming training instance in the scenariodo not limit a beamforming training scenario and a beamforming trainingprocess in this embodiment of the present disclosure. For example, inthe following scenario, the first device (corresponding to a STA4 in thefollowing scenario) participates in beamforming training as a deviceoutside a beamforming training group. In some application scenarios, thefirst device may also participate in beamforming training as a device inthe beamforming training group. For example, an initiator in thebeamforming training group indicates each responder in the traininggroup to perform an ISS only, and not to perform an RSS. In addition,the ISS training of the first device and the first beamforming trainingperformed by the first device as a device outside the beamformingtraining group in the foregoing embodiment may be separately performed.In the following specific beamforming training instance, to fullydescribe two processes in detail the ISS training of the first deviceand the first beamforming training of the first device serving as adevice outside the beamforming training group, the two processes arecombined for description.

FIG. 2 is a schematic diagram of a possible application scenario of thepresent disclosure. As shown in FIG. 2, the scenario includes an AP/PCPand a plurality of user equipments. The plurality of user equipments maydirectly communicate with each other or perform communication throughscheduling of the AP/PCP.

The user equipment mentioned in this application may include varioushandheld devices, in-vehicle devices, wearable devices, or computingdevices having a wireless communication function, or other processingdevices connected to a wireless modem, and various forms of userequipments (also referred to as UE), mobile stations (MSs), terminals,terminal equipment, STAs, and the like. For ease of description anddetailed description of this embodiment of the present disclosure, a STAis used as an example for description in this application.

In the scenario shown in FIG. 2, the user equipments are a STA1, a STA2,and a STA3. The STA1 serves as a beamforming training initiator, theSTA2 and the STA3 serve as beamforming training responders, and theSTA1, the STA2, and the STA3 form an SLS training group. It should benoted that a total quantity of member STAs (including the initiator STAsand all responder STAs) in the SLS training group should be greater thanor equal to two.

As shown in FIG. 3, a STA4 is an out-of-group STA that does not join theSLS training group. An address of the STA4 does not match a receiveaddress of an SSW frame/short SSW frame sent by the STA1. Because theSTA4 is not in an SLS training process of the STA1, the STA2, and theSTA3, the STA4 may be considered as a “hidden STA”. The receive addressof the SSW frame/short SSW frame may be represented by one of a MediaAccess Control (MAC) address of an individual type or a group type and agroup address identifier (also referred to as ID) (Group ID).

Based on a scenario shown in FIG. 3, this embodiment of the presentdisclosure provides a specific instance of the beamforming trainingmethod. According to the beamforming training method in this embodimentof the present disclosure, a beamforming training procedure and protocolin an SLS phase of 802.11ad are improved, to split an ISS and an RSSinto phases that can be independently completed and separately performedin terms of time such that a STA (for example, the STA4 in FIG. 3) whoseaddress does not match a receive address of a beamforming training framemay also participate in beamforming training in the ISS and/or RSS phasein real time as required, and skip completed beamforming training in asubsequent SLS training, thereby reducing training duration.

In addition, when an RXSS is usually performed in a BRP phase, in thebeamforming training method in this embodiment of the presentdisclosure, a multiple sector identifier (MID) subphase of the BRP mayalso be used for “one-to-many” beamforming training.

In the solution in this embodiment of the present disclosure, duringbeamforming training, possible reasons for including the STA that doesnot belong to the SLS training group are as follows.

(1) The STA4 does not obtain a transmission opportunity to send arequest to the initiator STA1 or an AP/PCP or negotiate to join the SLStraining group. For example, the STA4 wants to perform SLS training withthe STA1. However, before the STA1 obtains a transmission opportunity(TXOP)/SP used for the SLS training group, the STA4 fails to obtain achannel access opportunity to send an SLS training request message tothe STA1, the AP, or the PCP. This is likely to occur in a BSS withintensive STA deployment or heavy service load. Because of intensechannel access contention, the STA4 fails to obtain the channel accessopportunity to send the SLS training request message to the STA1 or theAP/PCP.

(2) Due to insufficient channel resources, the AP/PCP fails to allocatea sufficiently long beamforming training time to the STA1 to completeSLS training with a plurality of STAs. In the 802.11ad standard, ifthere is no sufficient time to complete SLS phase training in a CBAP, abeamforming training initiator should not initiate SLS phase training inthe CBAP. This indicates that if an initiator STA wants to initiate SLStraining with a plurality of STAs at the same time, but if the initiatorSTA can complete an SLS with only some responder STAs in the pluralityof responder STAs within a remaining time of the CBAP, remainingresponder STAs cannot participate in the SLS training of the initiatorSTA, and therefore the remaining responder STAs become hidden STAsoutside the SLS training group.

In addition, a reason that the ISS and the RSS need to be separated interms of time for independent execution may be as follows.

(3) In an SLS in downlink multi-user multiple-input multiple-output(MU-MIMO), only transmit beam training of the STA1 and receive beamtraining of user equipment (for example, the STA2 and the STA3) need tobe completed, and transmit beam training of the user equipment (forexample, the STA2 and the STA3) does not need to be performed. Forexample, if the downlink MU-MIMO is used, a best transmit beam of theSTA1 needs to be obtained through TXSS of an ISS, and a best receivebeam of each user equipment needs to be obtained through RXSS of an ISS.That is, only two ISSs are required without an RSS.

To join an SLS training group, a STA needs to send SLS training requestinformation to an initiator STA, an AP, or a PCP such that the initiatorSTA can request, based on a quantity of responder STAs in the SLStraining group and a quantity of transmit/receive sectors that eachresponder STA needs to sweep, the AP or the PCP to allocate asufficiently long time and a channel resource for beamforming trainingof the SLS training group. Therefore, if the STA fails to join in atimely manner, for the foregoing reasons, the SLS training groupinitiated by the initiator STA, the STA may serve as a “hidden STA” toparticipate in an SLS phase training with a target STA that wants toperform SLS training. The target STA may be the initiator STA, or may beany responder STA in the one or more responder STAs. The hidden STA is aSTA whose address does not match a receive address of a beamformingtraining frame (for example, an SSW frame or a short SSW frame) sent bythe initiator STA. The SLS training group includes one initiator STA andthe one or more responder STAs. When there is only one responder STA inthe SLS training group, the receive address of the beamforming trainingframe sent by the initiator STA is an individual address of theresponder STA. Otherwise, when there are a plurality of responder STAsin the SLS training group, the receive address of the beamformingtraining frame sent by the initiator STA is a group address, and anaddress of each responder STA in the SLS training group belongs to thereceive address of the beamforming training frame. The group address maybe represented by a group MAC address or a group ID.

In the beamforming training in this embodiment of the presentdisclosure, the ISS and the RSS may be independently performed in atime-separated form such that a STA that is not a member of thebeamforming training group can also directly participate in beamformingtraining in the ISS step and/or the RSS step. For a hidden STA, an SLSmay be divided into two phases.

First phase SLS: ISS or RSS training of an initiator STA or a responderSTA with a hidden responder STA.

As shown in FIG. 4, as a hidden responder, in a TXOP (namely, a CBAP) oran SP of an initiator STA1 and used for SLS training, a STA4 completesonly an ISS (including a TXSS or an RXSS of the initiator) of the STA1,but neither performs RSS (including a TXSS or an RXSS of the responder)of any hidden responder, nor sends sector sweep feedback information,for example, best sector information or SNR information of the ISS, tothe initiator STA. In FIG. 4, solid beams represent transmission of anSSW frame or a short SSW frame or a beamforming training sequence,whereas hollow beams represent reception of an SSW frame or a short SSWframe or a beamforming training sequence.

Second phase SLS: The original hidden responder STA serves as aninitiator, and the original initiator STA or responder STA serves as aresponder, to perform ISS training and/or RSS training. The RSS trainingusually includes only an RXSS of the responder.

As shown in FIG. 5, the STA4 completes, as an initiator STA, the RSSthat is not yet completed in the first phase SLS. In addition, becausethe STA1, as an initiator, has completed the TXSS or the RXSS of the ISSin the first phase SLS, the STA1 does not need to perform the TXSS orthe RXSS of the RSS as a responder in the second phase SLS, but maycomplete, as a responder, a TXSS or an RXSS that is not yet performed inthe first phase SLS. For example, because the STA1 has completed theTXSS of the ISS, but does not complete the RXSS of the ISS as aninitiator in the first phase, the STA1 does not need to perform the TXSSas a responder in the second phase SLS, but the STA1 may perform theRXSS of the RSS as a responder in the second phase SLS.

The hidden STA4 does not send a beamforming training feedback message(for example, an SSW-Feedback frame) in the first phase SLS. Generally,the first phase SLS and the second phase SLS belong to two differenttransmission resources, that is, belong to two different TXOPs or SPs.However, in the other approaches, a complete SLS should be completed inone TXOP or SP. In the present disclosure, a time interval between anend of the first phase SLS and a start of the second phase SLS isgreater than a medium beamforming interframe space MBIFS between an ISS,an RSS, SSW-Feedback, and SSW-Ack in the other approaches. Before thehidden STA initiates the second phase SLS as an initiator, it should bedetermined, based on estimated duration of the second phase SLS, thatthe best sector information is still valid when the second phase SLSends. To be specific, the STA4 determines that from obtaining of sectorselection information of the STA1 to the end of the ISS initiated by theSTA4, the sector selection information is within a preset beam linkmaintenance time. For example, when the best sector information isdetermined, a beam link maintenance timer is started. It is assumed thata time interval between the end of the first phase SLS and an end of thesecond phase SLS is L (displayed by the foregoing timer), and the hiddenSTA presets maximum duration K of a beam link valid state. The hiddenSTA should ensure that L is less than or equal to K before the start ofthe second phase SLS.

The following describes the beamforming training in this application indetail with reference to specific embodiments.

Embodiment 2

In Embodiment 2 of the present disclosure, an SLS phase includes thefollowing steps.

Step 1: A STA4 obtains a beamforming training time of a beamformingtraining group.

For example, the STA4 obtains, using a scheduling message sent by anAP/PCP, for example, using an extended schedule element and/or anenhanced directional multi-gigabit (DMG) (EDMG) extended scheduleelement, or using a received grant frame/grant acknowledgment (GrantAck) frame, a start time and duration of a CBAP/SP used for SLStraining, a channel included in the CBAP/SP, and a beamforming trainingtransmission mode, and identifies a target STA (for example, a STA1) ina training group participating in the SLS. For example, a start time andduration of the SLS may be obtained using an allocation field in theextended schedule element and/or the EDMG extended schedule element or adynamic allocation information (Dynamic Allocation Info) field of thegrant/grant Ack frame, and control information of the SLS is obtainedusing a beamforming control (BF Control) field.

Step 2: As shown in FIG. 4, as a hidden responder, the STA4 receives anSSW frame or a short SSW frame in an ISS phase or an RSS phase of thetarget STA (for brief description, in the present disclosure, the SSWframe is used to collectively represent the SSW frame or the short SSWframe), and completes TXSS training or RXSS training of the STA1.

The target STA may be an initiator STA or a responder STA in thebeamforming training group, and an ISS or an RSS of the target STA mayperform TXSS or RXSS training. The hidden responder is a STA that failsto send an SLS training request to the target STA, the AP, or the PCPand is not scheduled by the AP/PCP but still wants to perform SLStraining, namely, a STA whose address does not match a receive addressof any SSW frame or short SSW frame in the SLS.

The hidden responder serves as a receiver of the SSW frame or the shortSSW frame in the ISS/RSS of the target STA, but neither serves as aresponder to perform RSS training, nor feeds back, to the initiator STAin a first phase SLS, best sector information or SNR informationdetermined based on the received SSW frame or short SSW frame. It shouldbe noted that each STA in a beamforming training group may serve as areceiver of an SSW frame or a short SSW frame sent by a STA. To bespecific, when an address of any STA does not match a receive address(also referred to as RA) of the SSW frame or the short SSW frame, areceive address field of the SSW frame or short SSW frame may beignored.

For example, if the RA field of the SSW frame or the short SSW frameindicates an individual address or a group address, any STA whoseaddress does not match the RA address may perform the first phase SLStraining as a receiver of the SSW frame or the short SSW frame.

As shown in FIG. 6, the STA4 selects the initiator STA1 as the targetSTA for SLS training, and performs the TXSS or RXSS training initiatedby the STA1.

As shown in FIG. 7, the STA4 selects both the initiator STA1 and aresponder STA2 as target STAs for SLS training. In the ISS and RSSphases, the STA4 serves as a hidden responder outside an SLS traininggroup, and receives, through sweeping, an SSW frame or a short SSW framesent by the STA1 and the STA2 in order to complete partial SLS trainingof the STA1 and the STA2 in the first phase.

Step 3: As shown in FIG. 5, the STA4 (the original hidden responder)re-obtains a new channel time resource (SP/TXOP) as an initiator tocomplete second phase SLS training with the STA1 (the originalinitiator). The second phase SLS is a continuation of the first phaseSLS training, and the second phase SLS may have only an ISS but have noRSS.

Step 4: In a TXSS of the second phase SLS (the new SP/TXOP), an SSWframe or a short SSW frame sent by the STA4 includes best sectorinformation of the STA2 in the first phase SLS (a previous TXSS), forexample, one or more sector select ID (namely, a best sector ID) fields,and an antenna/radio frequency chain ID corresponding to each bestsector. As a new responder, the STA1 determines, based on a receivedvalue of the best sector ID field, to directly send an SSW-Feedbackframe without performing a responder TXSS.

If the STA1 performs an RXSS in the ISS in the first phase SLS, the STA1sends the SSW frame or the short SSW frame in a quasi-omni antenna modeor an antenna mode of a best transmit sector for the responder STA2.When the STA1 uses the quasi-omni antenna mode in the RXSS, a problemexisting when the STA4 performs RXSS training that a quantity of SSWframes or short SSW frames sent by the STA1 for the responder STA2cannot meet a requirement of the STA4 to perform the RXSS, that is, aquantity of SSW frames or short SSW frames sent by the STA1 is less thana quantity of receive sectors that the STA4 needs to sweep. When theSTA4 finds, using a countdown (CDOWN) field of the SSW frame or theshort SSW frame (as shown in FIG. 6, an initial value of the CDOWN fieldis N), that the total quantity of SSW frames or short SSW frames is lessthan the quantity of receive sectors that the STA4 needs to sweep, asshown in FIG. 8, when performing subsequent SLS training, the STA4 maysend a request message that includes RXSS length information to the STA1in order to request the STA1 to continue to perform the RXSS in thesecond phase SLS based on the RXSS length information, and completeunfinished sweeping of remaining receive sectors. For example, the STA4has 64 receive sectors, and the STA1 sends only 32 SSW frames or shortSSW frames for an RXSS of the STA2. In the first phase SLS trainingprocess shown in FIG. 6, the STA4 can sweep only 32 receivesectors/receive beams. As shown in FIG. 8, remaining 32 receive sectorsmay be swept in the RXSS of the STA1 in the second phase SLS.

In a beamforming training process shown in FIG. 5, that the STA1 doesnot perform RSS training may be explicitly indicated by the STA4 bysending a message. For example, a reserved field of an SSW frame/shortSSW frame/grant frame/SP request frame/BRP frame indicates a “no RSS(NoRSS) field” in order to indicate the STA1 not to perform the RSS as aresponder. The NoRSS may further include “no responder TXSS” or “noresponder RXSS” to respectively indicate the STA1 not to perform aresponder TXSS or a responder RXSS as a responder. The NoRSS field maybe included in a beamforming control field or an EDMG beamformingcontrol field of the SSW frame/short SSW frame/grant frame/SP requestframe/BRP frame, or may be included in a control trailer of theforegoing frame. In addition, the AP or the PCP may include, in a DMGbeacon frame or an announce frame, the received NoRSS field that isincluded by the initiator STA in beamforming training requestinformation, and sends the NoRSS field to a responder.

Alternatively, that the STA1 does not perform RSS training may beimplicitly indicated by the STA4 using another message. For example, asshown in FIG. 5, each SSW frame or short SSW frame that is sent by theSTA4 in a TXSS of the ISS phase in the second phase SLS includes a valueof a sector select/best sector ID field and a correspondingantenna/radio frequency chain ID. This indicates that the STA4 hasobtained a best transmit sector ID of the STA1 through SLS training inthe first phase. Therefore, the STA1 does not need to perform a TXSS ofthe RSS, but directly sends the SSW-Feedback frame or the SSW Ack frameto respond to the ISS of the STA4, and the STA4 sends an SSW Ack frameor an SSW-Feedback frame as a response. In addition, the best sector IDand the corresponding antenna/radio frequency chain ID may further beincluded in the grant frame, and the STA4 sends the grant frame to theSTA1. The STA1 does not need to perform the TXSS of the RSS.

Similarly, that the STA1 does not perform the responder RXSS trainingmay also be implicitly indicated by the STA4 using other messages. Forexample, when the STA4 completes the RXSS of the STA1 in the first phaseSLS, the STA4 may include, in the SSW/short SSW frame of the secondphase, a value that is indicated by an SNR report subfield of a transmitsector of the STA1 and that is obtained during the RXSS to indicate theSTA1 not to perform the responder RXSS.

The method in this embodiment may be applied not only to beamformingtraining in the SLS phase, but also to RXSS training in a MID subphasein a BRP phase. For example, a STA (for example, the STA4) serves as ahidden STA to participate in an RXSS training process of the STA1 in theMID subphase of the BRP phase of another pair of STAs (for example, theinitiator STA1 and the responder STA2) in order to obtain a best receivesector of the STA. When the STA4 subsequently performs SLS phasetraining with the STA1, the RXSS of the STA1 does not need to be furtherperformed such that a training time of the RXSS of the STA1 is reduced.It should be noted that, when the hidden STA participates in the RXSS inthe MID subphase of the BRP phase of the other pair of STAs, relatedinformation such as a start time and duration of the RXSS may beobtained using a beamforming control field carried by various managementframes such as a DMG beacon frame or a grant frame, or may be obtainedusing a field (for example, a beamforming control field or a DMG BRPelement) of each type of frame (for example, an SSW feedback/Ack frameor a BRP frame) negotiated for establishing the BRP phase.

Embodiment 3

FIG. 9 is a flowchart of a beamforming training method according toEmbodiment 3 of the present disclosure. As shown in FIG. 9, for SLStraining of downlink MU-MIMO, a best transmit beam of a data sending STA(STA1) needs to be obtained through a TXSS of an ISS, and a best receivebeam of each user equipment needs to be obtained through an RXSS of theISS. To be specific, in an SLS phase, only two ISS phases (a TXSS of theSTA1 and an RXSS of the STA1) of the initiator STA (STA1) are required,and an RSS is not required. This also indicates that in the downlinkMU-MIMO, an original SLS protocol that supports a bidirectional linkcannot fully support a training process of a unidirectional link in thedownlink MU-MIMO. Therefore, an SLS beamforming training protocol inwhich an ISS and an RSS are separately performed is required to fullysupport beamforming training using an SLS downlink (unidirectionallink).

In the present disclosure, beamforming training is intended to determineinformation about the best transmit beam and/or the best receive beam,and the information about the best transmit beam and the best receivebeam may be respectively represented by a best transmit sector ID and abest receive sector ID, and may further be respectively represented byIDs/sequence numbers of a best transmit antenna weight vector (AWV) anda best receive AWV. In addition, a sector may be represented by a beamor AWV instead.

Improvements of the solution in this embodiment of the presentdisclosure relative to the other approaches are as follows.

Decoupling between an ISS and an RSS: A reserved field of a beamformingcontrol field is used. For example, a NoRSS field is used to indicatewhether an RSS in a second phase SLS occurs. When indicating that thereis no RSS in the second phase SLS, the NoRSS field indicates a responderto directly send an SSW-Feedback frame or an SSW-Ack frame after an ISSends. For another example, a first bit and a second bit of the NoRSSfield respectively indicate “no responder TXSS” and “no responder RXSS”in order to respectively indicate enabling and disabling of a responderTXSS and a responder RXSS. Alternatively, a feedback of a sectorselect/best sector ID field is directly included in an SSW frame or ashort SSW frame in an ISS phase of the second phase SLS in order toindicate enabling and disabling of the RSS.

Modifying an existing SLS protocol: A TXSS at the beginning of the ISSis enabled to carry the best sector ID, the responder STA is enabled touse the SSW-Feedback frame originally used by an initiator only, and theinitiator is enabled to use the SSW Ack frame. In addition, the RXSS maybe split into two phases, which are respectively performed in a firstphase SLS and the second phase SLS. RXSS length information in thesecond phase SLS is used to indicate a quantity of remaining receivesectors/receive AWVs that are not swept in the first phase SLS.

Modifying a meaning of an address field of an SSW frame or a short SSWframe. For example, if an RA field is a broadcast/group address, itindicates that another STA, as a hidden STA, may perform phased SLSproposed in the present disclosure with the other STA, and a new phasedSLS completion time limit indication is added to indicate valid durationof a beamforming training result obtained in the first phase SLS.

Beneficial effects that can be achieved in the solution in thisembodiment of the present disclosure are as follows.

After the ISS and the RSS of the SLS are separated, a potential STA thatneeds to perform the SLS can flexibly participate in any TXSS/RXSS in anISS or an RSS in the first phase SLS in real time, and in the subsequentsecond phase SLS, a previously completed SLS phase is omitted in orderto reduce required total duration of the TXSS/RXSS.

When a TXSS of a STA takes a long time, for example, in FIG. 10, when aSTA1 has two large-scale phased-array antennas of 64 elements, and eachantenna has 128 transmit sectors, 256 SSW frames in total need to besent to complete a TXSS once. If a hidden STA wants to perform SLStraining with the STA1, the hidden STA may directly participate in aTXSS performed between the STA1 and another STA. In this way, the STA1is prevented from performing a TXSS again with the hidden STA, andreduced TXSS duration reaches 4.07 milliseconds (ms) (15.91 microseconds(μs)×256). Therefore, SLS duration can be significantly reduced. In theforegoing example, there are only 128 transmit sectors of one antenna ofthe STA1. When there are 1024 transmit sectors of one antenna of theSTA1, reduced TXSS duration can reach 32.56 ms.

According to this embodiment, normal beamforming training of an existingSLS training group is not interfered, and there is no problem thatscheduling or polling needs to be performed for a multi-user response inMU-MIMO beamforming training. The hidden STA receives only a sent SSWframe/TRN training sequence, and does not send an SSW frame or feedbacka beamforming training result. However, when beamforming training of atransmit link needs to be performed, the hidden STA performs beamformingtraining with a target STA as an initiator STA.

The present disclosure is particularly suitable for a scenario in whichone device performs beamforming training with a plurality of devices atthe same time. For example, in relay application, a relay device needsto maintain two links with a source device and a destination device.Therefore, during SLS training, even if the source device or thedestination device cannot send a beamforming training request to therelay device, the source device or the destination device mayparticipate in beamforming training of the relay device in real time,thereby reducing beamforming training time. In addition, in MU-MIMO, thepresent disclosure is also particularly suitable for a hidden device toparticipate in beamforming training in real time, and beamformingtraining that needs to be applied to a unidirectional link (only atransmit beam of a device and a receive beam of a peer device aretrained).

Embodiment 4

In an existing beamforming training method, when requesting a channelresource, a beamforming training initiator does not differentiatechannel characteristics. However, in an actual beamforming trainingprocess, a beam channel with a specific characteristic may need to betrained. It can be learned that an existing beamforming training channelallocation manner does not meet a training requirement of the channelwith the specific characteristic. To resolve this technical problem,this embodiment of the present disclosure provides a beamformingtraining method. In the method, when requesting or negotiating abeamforming training resource, a beamforming training initiator includesone or more types of training phase information, channel numberinformation, channel bandwidth information, channel transmission modeinformation, and information about a quantity of spatial flows of atraining sequence in beamforming training request information in orderto request a second device to allocate or negotiate to determine achannel that has a characteristic specified in the request informationfor beamforming training.

It should be noted that, the beamforming training initiator in thesolution in this embodiment of the present disclosure may be thebeamforming training initiator in the beamforming training group shownin FIG. 2, or may be the hidden device (for example, the STA4) outsidethe beamforming training group shown in FIG. 3.

FIG. 11 is a flowchart of a beamforming training method according toEmbodiment 4 of the present disclosure. As shown in FIG. 11, the methodincludes the following steps.

Step S201: A first device sends beamforming training request informationto a second device, where the beamforming training request informationincludes at least one of training phase information, channel numberinformation, channel bandwidth information, channel transmission modeinformation, and information about a quantity of spatial flows of atraining sequence.

Step S202: The first device receives configuration information fed backby the second device based on the beamforming training requestinformation.

Step S203: The first device performs beamforming training based on theconfiguration information.

In the implementation solution in this embodiment of the presentdisclosure, when requesting or negotiating a beamforming trainingresource, a beamforming training initiator (corresponding to the firstdevice) includes one or more of the training phase information, thechannel number information, the channel bandwidth information, thechannel transmission mode information, and the information about aquantity of spatial flows of a training sequence in the beamformingtraining request information in order to request the second device toallocate or negotiate to determine a channel that has a characteristicspecified in the request information for beamforming training.

In a possible design, the beamforming training request information isincluded in an SP request frame, a grant frame, or a grantacknowledgment frame.

In a possible design, the training phase information is used to indicatean SLS phase or a BRP phase.

In this implementation, the training phase information in thebeamforming training request information indicates the SLS phase or theBRP phase such that the second device allocates a channel resourcecorresponding to a corresponding training phase.

In a possible design, the channel number information is used to indicatewhether a channel with a specified number is requested for beamformingtraining.

In this implementation, the channel number information is used toindicate whether the channel with the specified number is requested suchthat the second device allocates the channel with the specified numberfor beamforming training.

In a possible design, when the channel number information indicates thatthe channel with the specified number is requested, or when the trainingphase information indicates the BRP phase, the channel bandwidthinformation is used to indicate one or more channel numbers, and whenthe channel number information indicates that the channel with thespecified number is not requested, or when the training phaseinformation indicates the SLS phase, the channel bandwidth informationis used to indicate a channel bandwidth.

In a possible design, the channel transmission mode information is usedto indicate whether a beamforming training sequence uses a channelaggregation mode or a channel bonding mode.

In a possible design, when the training phase information indicates theBRP phase, the information about a quantity of spatial flows of atraining sequence is used to indicate a quantity of transmit spatialflows of a training field.

Corresponding to the method in Embodiment 4, this application furtherprovides Embodiment 5.

Embodiment 5

FIG. 12 is a flowchart of a beamforming training method according toEmbodiment 5 of the present disclosure. As shown in FIG. 12, the methodincludes the following steps.

Step S301: A second device receives beamforming training requestinformation sent by a first device, where the beamforming trainingrequest information includes at least one of training phase information,channel number information, channel bandwidth information, channeltransmission mode information, and information about a quantity ofspatial flows of a training sequence.

Step S302: The second device allocates, to the first device based on thebeamforming training request information, a channel used for beamformingtraining.

In an existing beamforming training method, when requesting a channelresource, a beamforming training initiator does not differentiatechannel characteristics. Correspondingly, when allocating a channel atthe request of the first device, the second device does notdifferentiate channel resource characteristics. In the solution in thisembodiment of the present disclosure, when requesting or negotiating abeamforming training resource, a beamforming training initiator(corresponding to the first device) includes one or more types of thetraining phase information, the channel number information, the channelbandwidth information, the channel transmission mode information, andthe information about a quantity of spatial flows of a training sequencein the beamforming training request information. Therefore, whenallocating a channel resource to the first device or negotiating withthe first device to determine a channel resource, the second deviceallocates a channel resource based on a channel characteristic specifiedin the beamforming training request information.

In a possible design, the beamforming training request informationincludes the training phase information and/or the channel numberinformation, and further includes the channel bandwidth information,when the training phase information indicates an SLS phase, and/or thechannel number information in the beamforming training requestinformation indicates that a channel with a specified number is notrequested, the channel bandwidth information is used to indicate achannel bandwidth, and allocating, by the second device to the firstdevice based on the beamforming training request information, a channelused for beamforming training includes allocating, by the second deviceto the first device, a channel whose channel bandwidth is less than orequal to the channel bandwidth indicated by the channel bandwidthinformation.

In a possible design, the beamforming training request informationincludes the training phase information and/or the channel numberinformation, and further includes the channel bandwidth information,when the training phase information indicates a BRP phase, and/or thechannel number information in the beamforming training requestinformation indicates that a channel with a specified number isrequested, the channel bandwidth information is used to indicate one ormore channel numbers, and allocating, by the second device to the firstdevice based on the beamforming training request information, a channelused for beamforming training includes allocating, by the second deviceto the first device, at least one channel whose channel number isindicated by the channel bandwidth information.

In a possible design, the beamforming training request informationincludes the channel bandwidth information, and the channel bandwidthinformation indicates zero, and the allocating, by the second device tothe first device based on the beamforming training request information,a channel used for beamforming training includes allocating, by thesecond device, any single channel to the first device.

In a possible design, the beamforming training request informationincludes the channel transmission mode information, and the channeltransmission mode information is used to indicate whether a beamformingtraining sequence uses a channel aggregation mode or a channel bondingmode, and allocating, by the second device to the first device based onthe beamforming training request information, a channel used forbeamforming training includes allocating, by the second device to thefirst device, a channel whose channel mode is the same as a channel modeindicated by the channel transmission mode information.

In a possible design, the beamforming training request informationincludes the information about a quantity of spatial flows of a trainingsequence and the training phase information, and when the training phaseinformation indicates the BRP phase, the information about a quantity ofspatial flows of a training sequence is used to indicate a quantity oftransmit spatial flows of a training field, and allocating, by thesecond device to the first device based on the beamforming trainingrequest information, a channel used for beamforming training includesallocating, by the second device to the first device, a channel for BRPtraining and with a quantity of spatial flows the same as the quantityof spatial flows indicated by the information about a quantity ofspatial flows of a training sequence.

The following describes the beamforming training method in thisembodiment of the present disclosure in detail with reference tospecific instances.

Similar to the 802.11ad standard, beamforming training is divided intotwo phases, an SLS and a BRP. The SLS phase is intended to establish aninitial link between two devices such that a physical layer protocoldata unit (PPDU) in a control mode can be transmitted. However, in theBRP phase, based on the initial link established in the SLS phase,training is further performed for a receive beam (RX beam)/receive AWV(RX AWV), and beam combining measurement is performed between a transmitsector/transmit AWV and a receive sector/receive beam/receive AWV inorder to better align a transmit beam and a receive beam, and toestablish a best link between a receive device and a transmit device.

It can be learned from functional division between the SLS and the BRPthat the SLS is intended to quickly establish the initial link toimplement exchange of some management control information, while qualityof the initial link is usually not the best. In the BRP, beam refinementis further performed based on the existing initial link in order toestablish the best link for data transmission. In a millimeter wave band(for example, a 60 GHz band), a best link (regardless of a single-inputsingle-output (SISO) link or a MIMO link) between a receive STA and atransmit STA is frequency-related, namely, channel-related. To bespecific, transmit or receive beams/sectors corresponding to best linksobtained by performing beamforming training on different channels may bedifferent. Therefore, in addition to some special application scenarios,beamforming training in the SLS phase does not need to be distinguishedbetween specific or particular channels. However, beamforming trainingin the BRP phase needs to be distinguished between specific orparticular channels on which the beamforming training is performed. Thespecial application scenarios mainly include an initiator STA wants toperform parallel training between a plurality of transmit antennas and aplurality of receive antennas using a plurality of channels and amulti-beamforming method in order to accelerate SLS phase trainingbetween the initiator STA and one or more responder STAs.

A channel mode in beamforming training in the BRP phase means that thereis a channel aggregation (also referred to as CA) mode and a channelbonding (also referred to as CB) mode in a draft of the 802.11aystandard. As shown in FIG. 13, channel aggregation means that for aplurality of channels, each channel uses a same transmission mode (forexample, each channel uses a DMG physical layer sending method in the802.11ad standard and uses a center frequency, a transmission bandwidthdefinition, and the like that are the same as those in the 802.11adstandard), and a guard band between two channels is not used duringtransmission. As shown in FIG. 14, the channel bonding transmission modemay also be referred to as a wideband (also referred to as WB) mode, andis a mode in which a new center frequency is used during transmission ona plurality of channels, and a guard band between adjacent channels isalso used for transmission.

In a case of SISO or MIMO, when an initiator STA requests an AP/PCP toallocate one or more channels for beamforming training, or negotiates achannel for beamforming training with one or more target STAs (responderSTAs), indication information needs to be sent. The indicationinformation is used to indicate channel number information forbeamforming training or channel bandwidth information for beamformingtraining.

The indication information needs to be classified into the channelnumber information and the channel bandwidth information, because a 400megahertz (MHz) guard band exists between adjacent channels of a 60 GHzband, and different training results may be obtained through beamformingtraining (in particular, in the BRP phase) in the channel aggregationmanner or the channel bonding manner, and different training results aremore likely to occur in a case of a relatively large quantity ofantennas and a relatively narrow beam. Therefore, for the beamformingtraining, it needs to be determined, based on a service data sendingmanner (channel aggregation or channel bonding), whether a beamformingtraining sequence (for example, an automatic gain control (AGC) andtraining (TRN) subfield, an SSW frame or a short SSW frame, or abeamforming training sequence based on orthogonal frequency divisionmultiplexing (OFDM) modulation) uses the channel aggregation sendingmanner.

Based on a difference between requesting an AP/PCP to allocate a channeland directly contending for accessing a channel for beamformingtraining, the following two cases may be included.

Case 1: An Initiator STA Requests the AP/PCP to Allocate One or MoreChannels for Beamforming Training in an SLS Phase.

When SLS phase training is performed between a pair of receive andtransmit STAs (a STA1 and a STA2), for example, when a link has neverbeen established between the STA1 and the STA2 before, or when anoriginally established link is interrupted due to a reason such asdevice movement or antenna rotation, the SLS phase beamforming trainingneeds to be performed to re-establish an initial link.

In addition to multi-beamforming training in the SLS phase performedusing a plurality of channels, to reduce power consumption, beamformingtraining in the SLS phase may be performed only on a single channel (forexample, a channel with a 2.16 GHz bandwidth). In this case, inbeamforming training request information sent by the initiator STA forbeamforming training in the SLS phase, only required channel bandwidthinformation needs to be indicated, and channel number information doesnot need to be indicated.

Further, the beamforming training request information sent by theinitiator STA to the AP/PCP may be included in an SPR frame, a grantframe, or a grant acknowledgment frame, for example, included in a newlydefined EDMG beamforming control field, a newly defined EDMG dynamicallocation information field, and/or a beamforming control field. TheEDMG beamforming control field and the EDMG dynamic allocationinformation (newly defined EDMG beamforming) field may be defined in acontrol trailer of the SP request frame.

Based on different application scenarios, the beamforming trainingrequest information carries at least one type of training phaseinformation, channel number information, channel bandwidth information,channel transmission mode information, and information about a quantityof spatial flows of a training sequence. Content that can be carried inthe beamforming training request information is shown in Table 1. Thetraining phase information and the channel number information may beinterchangeable, and only one piece is retained. Specific contentcarried in the channel bandwidth information is indicated by thetraining phase information or the channel number information. Thechannel transmission mode information is applicable only to a BRP phase.

TABLE 1 Content that can be carried in the beamforming training requestinformation 1. Training 2. Channel 3. Channel 4. Channel 5. Informationphase number bandwidth transmission about a information informationinformation mode quantity information of spatial flows of a trainingsequence

The training phase information is used to indicate whether the initiatorSTA requests beamforming training in an SLS phase or a BRP phase. Forexample, some bits of a beamforming control field or an EDMG beamformingcontrol field are used to newly define an “SLS training subfield” tocarry the training phase information. When the “SLS training subfield”is set to 1, it indicates that the initiator STA requests beamformingtraining in the SLS phase. When the “SLS training subfield” is set to 0,it indicates that the initiator STA requests beamforming training in theBRP phase.

The channel number information indicates whether a channel with aspecified channel number is specified for beamforming training, or thatis, indicates whether the AP/PCP allocates a channel based on arequested channel number for beamforming training, or indicates whethera peer STA contends for accessing a channel based on a requested channelnumber to complete beamforming training. The channel number informationis used to indicate whether the channel bandwidth information indicatesa channel bandwidth or a channel number.

For example, some bits of a beamforming control field or an EDMGbeamforming control field are used to newly define a “specified channelnumber subfield” to indicate the channel number information. When the“specified channel number subfield” is set to 1, it indicates that thechannel bandwidth information carries a channel number, and is used torequest the AP/PCP to allocate, based on the channel number, a channelcorresponding to the channel number, or request a responder STA toperform beamforming training on a channel corresponding to the channelnumber. When the “specified channel number subfield” is set to 0, itindicates that the channel bandwidth information carries a channelbandwidth, and is used to request the AP/PCP to allocate, based on thechannel bandwidth, any channel whose bandwidth is less than or equal tothe bandwidth.

A channel number usually does not need to be specified in the SLS.Therefore, the channel number information may be replaced by thetraining phase information. Correspondingly, the “specified channelnumber subfield” may be replaced by the “SLS training subfield”. Whenthe “SLS training subfield” is set to 1, it indicates that the channelbandwidth information carries a channel bandwidth, and is used torequest the AP/PCP to allocate any channel with a correspondingbandwidth based on the channel bandwidth. When the “SLS trainingsubfield” is set to 0, it indicates that the channel bandwidthinformation carries a channel number, and is used to request the AP/PCPto allocate, based on the channel number, a channel corresponding to thechannel number, or request the responder STA to perform beamformingtraining on a channel corresponding to the channel number.

The channel bandwidth information indicates a requested channelbandwidth or channel number used for beamforming training. When X (X isa positive integer) channels exist in a basic service set BSS of theAP/PCP, the channel bandwidth information may be an indication form thesame as a bandwidth subfield in an EDMG header A field or a legacyheader channel bandwidth (also referred to as Channel BW) field. Forexample, X bits in an EDMG beamforming control field or a beamformingcontrol field are newly defined as an EDMG-BW subfield to carry thechannel bandwidth information, and a channel bandwidth or a channelnumber for beamforming training is indicated in a channel bitmap manner.When the newly defined EDMG-BW subfield is used to indicate the channelnumber, if one bit of the EDMG-BW subfield is set to 1, it indicatesthat a corresponding channel is requested for beamforming training. Forexample, a bit 0 corresponds to a channel 1, a bit 1 corresponds to achannel 2, and so on. There may be a plurality of EDMG-BW subfields, forexample, EDMG-BW1, EDMG-BW2, and EDMG-BW3. An advantage of using theplurality of EDMG-BW subfields is that a channel selection range of theAP/PCP is expanded and scheduling flexibility is improved such that theAP/PCP can select one or more channels from all channels indicated bythe plurality of EDMG-BW subfields for allocation. Alternatively, theEDMG beamforming control field or the beamforming control field directlyindicates a channel number or a channel bandwidth in a numeralindication manner. The channel bandwidth may be represented by aquantity of channels.

When the SLS training subfield is set to 1 and/or the specified channelnumber subfield is equal to 0, it indicates that the initiator STA doesnot need to request or specify a specific channel indicated by thechannel number, and the EDMG-BW subfield indicates a requested channelbandwidth for beamforming training or a maximum channel bandwidth. Inthis case, the AP or the PCP may allocate, based on the EDMG-BWsubfield, any channel whose bandwidth is less than or equal to thebandwidth indicated by the EDMG-BW subfield. For example, when theEDMG-BW subfield indicates that the requested channel bandwidth forbeamforming training or the maximum channel bandwidth is a bandwidth ofa single channel 2.16 GHz, and an operating channel of the AP or the PCPincludes a channel 1, a channel 2, and a channel 3, the AP or the PCPmay allocate any one of the channel 1, the channel 2, and the channel 3to the initiator STA for beamforming training.

When the SLS training subfield is set to 0, and/or the channel numberinformation is equal to 1, the EDMG-BW subfield indicates a requestedchannel number for beamforming training.

Because beamforming training occupies at least one channel, when theEDMG-BW subfield indicates channel bandwidth or channel numberinformation, the channel bandwidth/channel number information can becarried only when a value is greater than 0. Therefore, when a value ofthe channel number subfield is equal to 0, the channel number subfieldmay also be used to indicate to request a single channel (for example, aprimary channel or a secondary channel).

The channel transmission mode information is used to indicate whether atransmission mode used for requested beamforming training is a channelaggregation mode, to be specific, whether a beamforming trainingsequence (AGC and TRN subfields of a BRP frame) is sent in a channelaggregation mode. A training sequence aggregation (TRN Aggregation)subfield is defined to indicate whether AGC and TRN fields in a PPDU usethe channel aggregation mode. Similarly, the training sequenceaggregation subfield may be defined like a channel aggregation subfieldin the EDMG-Header-A field. To be specific, when the training sequenceaggregation subfield is set to 0, it indicates that a training sequencein the requested beamforming training is the channel bondingtransmission mode or a single channel transmission mode, and when thetraining sequence aggregation subfield is set to 1, it indicates that atraining sequence in the requested beamforming training is the channelaggregation transmission mode. The channel transmission mode is referredto as a channel mode for short, and includes the channel aggregationmode or the channel bonding mode. Beamforming training in the channelaggregation transmission mode means that a sequence part used forbeamforming training, for example, AGC, training, and SSW frame/shortSSW frame (the entire PPDU or a preamble field) of a training sequenceof a BRP packet uses the channel aggregation transmission mode.Beamforming training in the channel bonding transmission mode means thatthe sequence part used for beamforming training uses the channel bondingtransmission mode.

As shown in FIG. 15, the beamforming training in the BRP phase uses thechannel aggregation manner, to be specific, the AGC and TRN subfieldsused as beamforming training sequences all use the channel aggregationtransmission mode. As shown in FIG. 16, the beamforming training in theBRP phase uses the channel bonding manner, to be specific, the AGC andTRN subfields used as beamforming training sequences all use the channelbonding transmission mode.

The information about a quantity of spatial flows of a trainingsequence. When the training phase information indicates the BRP phase,the information about a quantity of spatial flows of a training sequenceis used to indicate a quantity of transmit spatial flows of a trainingfield. The training field is a field corresponding to the beamformingtraining sequence, for example, the AGC and TRN subfields. Otherwise,when the training phase information indicates the SLS phase, theinformation about a quantity of spatial flows of a training sequenceindicates a quantity of transmit spatial flows of an SLS frame. Becausea training sequence in MIMO may use a parallel sending MIMO trainingmanner, a receiver of the training sequence needs to implement correctreceive antenna configuration based on the information about a quantityof spatial flows of a training sequence such that a time of beamformingtraining is shortened in a fast MIMO training manner.

The beamforming training sequence is intended to obtain a best antennaconfiguration for subsequent data transmission through training.Therefore, whether the beamforming training sequence uses the channelaggregation transmission mode depends on which transmission mode, thechannel bonding or channel aggregation transmission mode, is used forsubsequent data transmission. When the initiator STA/responder STAseparately performs beamforming training using a PPDU (for example, aRequest to Send (RTS) frame, a Clear to Send (CTS) frame, a grant frame,a decline transmit (DTS) frame, or a grant acknowledgment frame) in acontrol mode, or a BRP packet (for example, a single carrier mode (SCMode) PPDU or a low power SC mode PPDU or an OFDM mode PPDU), whether atraining field (for example, the AGC and TRN subfields) uses the channelaggregation transmission mode or the channel bonding transmission modeand/or the quantity of transmit spatial flows of a training fieldneed/needs to be indicated. Because in the sending manners shown in FIG.15 and FIG. 16, sending is usually performed by the RTS frame/CTS frame,the channel transmission mode information and the information about aquantity of spatial flows of a training sequence are further included inthe EDMG-Header-A field of the PPDU such that the receiver can quicklyobtain the channel transmission mode information and the informationabout a quantity of spatial flows of a training sequence by decoding andparsing the EDMG-Header-A field, and use corresponding receive antennaconfigurations and training modes for the AGC and TRN subfields, toproperly receive the AGC and TRN subfields of the training sequence in acorrect receiving manner. The channel transmission mode information andthe information about a quantity of spatial flows of a training sequencemay further be included in a control trailer field of the PPDU.

In the solution in this embodiment of the present disclosure, as areceiver of the beamforming training request information, the AP/PCPschedules/allocates, for the initiator STA based on the receivedbeamforming training request information of the initiator STA, a channelused for beamforming training, and includes a specific trainingparameter configuration of beamforming training in allocationinformation. The allocation information may be carried in an extendedscheduling element and/or an EDMG extended scheduling element.

The training parameter includes at least one of an SLS trainingsubfield, an EDMG-BW subfield, a TRN aggregation subfield, and atraining sequence spatial flow quantity subfield. When the SLS trainingsubfield received by the AP/PCP is set to 1, and/or the channel numbersubfield is specified to be equal to 0, it indicates that the initiatorSTA does not need to request or specify a specified channel indicated bya channel number, and the EDMG-BW subfield indicates a requested channelbandwidth for beamforming training or a maximum channel bandwidth. Inthis case, the AP/PCP allocates, based on the requested channelbandwidth for beamforming training or the maximum channel bandwidthindicated by the EDMG-BW subfield, any channel whose bandwidth is lessthan or equal to the bandwidth indicated by the EDMG-BW subfield withinan operating channel range of the BSS, and allocates a channel whosechannel type (channel aggregation or channel bonding) is the same as thechannel type requested by the initiator, and indicates a quantity ofspatial flows of a training sequence the same as a requested quantity ofspatial flows of a training sequence.

For example, if training phase information sent by an initiator STAindicates to request to perform beamforming training in the SLS phase, arequested bandwidth is a bandwidth (4.32 GHz) of two channels, TRNaggregation subfield indicates channel bonding, and an operating channelof the AP/PCP includes channels 1 to 3, the AP/PCP may allocate achannel time (on the channel 1 and the channel 2) or a channel time (onthe channel 2 and the channel 3) to the initiator STA for beamformingtraining.

When the SLS training subfield is set to 0, and/or the channel numberinformation is equal to 1, the EDMG-BW subfield indicates a requestedchannel number for beamforming training. In this case, the AP/PCPallocates, based on a channel number indicated by the EDMG-BW subfield,a channel corresponding to the channel number for beamforming training.The allocation information is included in a DMG beacon frame, anannounce frame, or a grant acknowledgment frame.

When the EDMG-BW subfield indicates 0, the AP/PCP allocates any singlechannel within an operating channel range for beamforming training.

Case 2: An Initiator STA Directly Sends a Beamforming Training Requestto a Responder STA in a CBAP.

When the initiator STA and the responder STA separately negotiate abeamforming training channel using a grant frame and a Grant Ack frame,a format of beamforming training request information carried in thegrant frame is the same as a format of beamforming training requestinformation sent by the initiator STA using an SPR frame, andbeamforming training acknowledgment information carried in the Grant Ackframe is used to confirm whether beamforming training can be performedbased on a beamforming training parameter indicated by the beamformingtraining request information.

FIG. 17 is a schematic diagram of beamforming training in a channelbonding manner negotiated using a grant frame/grant acknowledgment framewithin a CBAP. FIG. 18 is a schematic diagram of beamforming training ina channel aggregation manner negotiated using a grant frame/grantacknowledgment frame in a CBAP. In FIG. 17 and FIG. 18, beamformingtraining in the channel bonding or channel aggregation manner that usestwo channels and is negotiated using the grant frame/grantacknowledgment frame is implemented.

The foregoing method is particularly suitable for the AP/PCP to allocatea proper channel for “point-to-multipoint” MU-MIMO beamforming trainingor a STA in Embodiment 1. The initiator STA determines, based on abeamforming training phase (SLS/BRP) and/or a beamforming trainingrequirement (whether the SLS phase is MU-MIMO beamforming training orwhether the STA in Embodiment 1 has completed partial SLS training), torequest one or more channel numbers or only a channel bandwidth from theAP/PCP. Compared with requesting only one channel number, a plurality ofchannel numbers or only a channel bandwidth requested from the AP/PCP ismore likely to be allocated to a required channel resource forbeamforming training such that channel resources are used flexibly andefficiently without reducing beamforming training performance.

Embodiment 4 and Embodiment 5 and method instances corresponding toEmbodiment 4 and Embodiment 5 of the present disclosure may be appliedto a scenario in which an initiator STA in a beamforming training grouprequests a beamforming training resource from an AP/PCP, or may beapplied to a scenario in which a hidden STA requests a beamformingtraining resource from an AP/PCP, and further may be applied to ascenario in which STAs negotiate a beamforming training resource.

For Embodiment 4, Embodiment 5, and corresponding instances, that theinitiator STA determines channel number information based on abeamforming training phase (SLS/BRP) and/or a multi-beamforming mannerfurther includes the following.

a. In a case of non-multi-beamforming, only a single channel needs to beused for beamforming training in the SLS phase.

b. In a multi-beamforming manner, a channel number is required in theSLS phase.

c. In the BRP phase, one or more channel numbers are required.

Further, the channel bandwidth information is used to indicate a channelbandwidth or a channel number. The channel transmission mode informationis used to indicate whether a beamforming training sequence or frame ischannel aggregation.

FIG. 19 is a schematic structural diagram of a beamforming trainingapparatus according to an embodiment of the present disclosure. Theapparatus shown in FIG. 19 is configured to perform the beamformingtraining method performed by the first device in Embodiment 1 and theSTA4 in the instance corresponding to Embodiment 1, the STA4 inEmbodiment 2, and the STA1 in Embodiment 3. The following describes amain function of the beamforming training apparatus. For a part that isnot described, refer to Embodiment 1 to Embodiment 3 and theaccompanying drawings in Embodiment 1 to Embodiment 3.

The beamforming training apparatus includes a sending unit 401 and areceiving unit 402.

The sending unit 401 is configured to send first indication informationto a second device, where the first indication information indicates thesecond device not to perform an RSS, and send a sector sweep frame of anISS to the second device. The receiving unit 402 is configured toreceive feedback information obtained by the second device during theISS.

In a possible design, before the sending unit 401 sends the sector sweepframe of the ISS to the second device, the receiving unit 402 is furtherconfigured to receive a sector sweep frame of first beamforming trainingof the second device, where an address of the first device does notmatch a receive address of the sector sweep frame of the firstbeamforming training.

The apparatus further includes a first processing unit 403 configured todetermine sector selection information or SNR information of the firstbeamforming training based on the received sector sweep frame of thesecond device.

In a possible design, the first beamforming training includes an ISSand/or the RSS of the second device.

In a possible design, that the first processing unit 403 determinessector selection information or SNR information of the first beamformingtraining based on the received sector sweep frame of the second devicefurther includes, when the first beamforming training includes a TXSS ofthe second device, determining the sector selection information of thesecond device based on the sector sweep frame of the second device.

In a possible design, that the first processing unit 403 determinessector selection information or SNR information of the first beamformingtraining based on the received sector sweep frame of the second devicefurther includes, when the first beamforming training includes an RXSSof the second device, determining whether a quantity of sector sweepframes sent by the second device is greater than or equal to a quantityof receive sectors that the first device needs to sweep, and if thequantity of sector sweep frames sent by the second device is greaterthan or equal to the quantity of receive sectors that the first deviceneeds to sweep, determining SNR information of a transmit sector of thefirst device based on the received sector sweep frame of the seconddevice.

In a possible design, if the quantity of sector sweep frames sent by thesecond device is less than the quantity of receive sectors to be sweptby the first device, the sending unit 401 is further configured to sendsecond indication information to the second device, where the secondindication information is used to indicate RXSS length information of aresponder RXSS of the second device after the ISS of the first device.

In a possible design, the first indication information is indicationinformation used to indicate the second device not to perform aresponder TXSS and/or a responder RXSS after the ISS of the firstdevice.

In a possible design, the first indication information is included in asector sweep SSW frame or a short SSW frame of the ISS of the firstdevice, or included in a grant frame or an SP request frame.

In a possible design, the first indication information is the sectorselection information or the SNR information.

In a possible design, the apparatus further includes a second processingunit 404 configured to, before the sending unit 401 sends the firstindication information, determine that when the ISS of the first deviceends, the sector selection information is within a preset beam linkmaintenance time.

In a possible design, after the receiving unit 402 receives the feedbackinformation obtained by the second device during the ISS, the sendingunit 401 is further configured to send a sector sweep frame of secondbeamforming training to the second device, and the receiving unit 402 isfurther configured to receive sector selection information or SNRinformation, based on the second beamforming training, of the seconddevice.

In a possible design, the ISS of the first device is an initiator TXSS,and the second beamforming training is an initiator RXSS, or the ISS ofthe first device is an initiator RXSS, and the second beamformingtraining is an initiator TXSS.

In another possible design, the beamforming training apparatus includesa receiver, a transmitter, and a processor. The receiver is configuredto implement a function of the receiving unit 402 in FIG. 19, thetransmitter is configured to implement a function of the sending unit401 in FIG. 19, and the processor is configured to implement functionsof the first processing unit 403 and the second processing unit 404 inFIG. 19.

FIG. 20 is a schematic structural diagram of another beamformingtraining apparatus according to an embodiment of the present disclosure.The apparatus shown in FIG. 20 is configured to perform the beamformingtraining method performed by the first device in Embodiment 4 and thedevice configured to send the beamforming training request informationin the instance corresponding to Embodiment 4. The following describes amain function of the beamforming training apparatus. For a part that isnot described, refer to Embodiment 4 and the instance corresponding toEmbodiment 4, and the accompanying drawings in Embodiment 4 and thecorresponding instance.

The beamforming training apparatus includes a sending unit 501, areceiving unit 502, and a beamforming training unit 503.

The sending unit 501 is configured to send beamforming training requestinformation to a second device, where the beamforming training requestinformation includes at least one type of the following informationtraining phase information, channel number information, channelbandwidth information, channel transmission mode information, andinformation about a quantity of spatial flows of a training sequence.

The receiving unit 502 is configured to receive configurationinformation fed back by the second device based on the beamformingtraining request information.

The beamforming training unit 503 is configured to perform beamformingtraining based on the configuration information.

In a possible design, the beamforming training request information isincluded in an SP request frame, a grant frame, or a grantacknowledgment frame.

In a possible design, the training phase information is used to indicatean SLS phase or a BRP phase.

In a possible design, the channel number information is used to indicatewhether a channel with a specified number is requested for beamformingtraining.

In a possible design, when the channel number information indicates thatthe channel with the specified number is requested, or when the trainingphase information indicates the BRP phase, the channel bandwidthinformation is used to indicate one or more channel numbers, and whenthe channel number information indicates that the channel with thespecified number is not requested, or when the training phaseinformation indicates the SLS phase, the channel bandwidth informationis used to indicate a channel bandwidth.

In a possible design, the channel transmission mode information is usedto indicate whether a beamforming training sequence uses a channelaggregation mode or a channel bonding mode.

In a possible design, when the training phase information indicates theBRP phase, the information about a quantity of spatial flows of atraining sequence is used to indicate a quantity of transmit spatialflows of a training field.

In another possible design, the beamforming training apparatus includesa receiver, a transmitter, and a processor. The receiver is configuredto implement a function of the receiving unit 502 in FIG. 20, thetransmitter is configured to implement a function of the sending unit501 in FIG. 20, and the processor is configured to implement a functionof the beamforming training unit 503 in FIG. 20.

FIG. 21 is a schematic structural diagram of yet another beamformingtraining apparatus according to an embodiment of the present disclosure.The apparatus shown in FIG. 21 is configured to perform the beamformingtraining method performed by the second device in Embodiment 5 and thedevice configured to receive the beamforming training requestinformation in the instance corresponding to Embodiment 5. The followingdescribes a main function of the beamforming training apparatus. For apart that is not described, refer to Embodiment 5 and the instancecorresponding to Embodiment 5, and the accompanying drawings inEmbodiment 5 and the corresponding instance.

The beamforming training apparatus includes a receiving unit 601 and anallocation unit 602.

The receiving unit 601 is configured to receive beamforming trainingrequest information sent by a first device, where the beamformingtraining request information includes at least one type of trainingphase information, channel number information, channel bandwidthinformation, channel transmission mode information, and informationabout a quantity of spatial flows of a training sequence.

The allocation unit 602 is configured to allocate, to the first devicebased on the beamforming training request information, a channel usedfor beamforming training.

In a possible design, the beamforming training request informationincludes the training phase information and/or the channel numberinformation, and further includes the channel bandwidth information,when the training phase information indicates an SLS phase, and/or thechannel number information in the beamforming training requestinformation indicates that a channel with a specified number is notrequested, the channel bandwidth information is used to indicate achannel bandwidth, and that the allocation unit 602 allocates, to thefirst device based on the beamforming training request information, achannel used for beamforming training includes allocating, to the firstdevice, a channel whose channel bandwidth is less than or equal to thechannel bandwidth indicated by the channel bandwidth information.

In a possible design, the beamforming training request informationincludes the training phase information and/or the channel numberinformation, and further includes the channel bandwidth information,when the training phase information indicates a BRP phase, and/or thechannel number information in the beamforming training requestinformation indicates that a channel with a specified number isrequested, the channel bandwidth information is used to indicate one ormore channel numbers, and that the allocation unit 602 allocates, to thefirst device based on the beamforming training request information, achannel used for beamforming training further includes allocating, tothe first device, at least one channel whose channel number is indicatedby the channel bandwidth information.

In a possible design, the beamforming training request informationincludes the channel bandwidth information, and the channel bandwidthinformation indicates zero, and the allocating, by the second device tothe first device based on the beamforming training request information,a channel used for beamforming training includes allocating, by thesecond device, any single channel to the first device.

In a possible design, the beamforming training request informationincludes the channel transmission mode information, and the channeltransmission mode information is used to indicate whether a beamformingtraining sequence uses a channel aggregation mode or a channel bondingmode, and that the allocation unit 602 allocates, to the first devicebased on the beamforming training request information, a channel usedfor beamforming training includes allocating, to the first device, achannel whose channel mode is the same as a channel mode indicated bythe channel transmission mode information.

In a possible design, the beamforming training request informationincludes the information about a quantity of spatial flows of a trainingsequence and the training phase information, and when the training phaseinformation indicates the BRP phase, the information about a quantity ofspatial flows of a training sequence is used to indicate a quantity oftransmit spatial flows of a training field, and that the allocation unit602 allocates, to the first device based on the beamforming trainingrequest information, a channel used for beamforming training includesallocating, to the first device, a channel for BRP training and with aquantity of spatial flows the same as the quantity of spatial flowsindicated by the information about a quantity of spatial flows of atraining sequence.

In another possible design, the beamforming training apparatus includesa receiver, a transmitter, and a processor. The receiver is configuredto implement a function of the receiving unit 601 in FIG. 21, thetransmitter is configured to implement a function of the sending unit inFIG. 20, and the processor is configured to implement a function of theallocation unit 602 in FIG. 21.

It may be understood that, the processor mentioned in the embodiments ofthe present disclosure may be a central processing unit (CPU), ageneral-purpose processor, a digital signal processor (DSP), anapplication-specific integrated circuit (ASIC), a field programmablegate array (FPGA) or another programmable logic device, a transistorlogic device, a hardware component, or any combination thereof. Theprocessor may implement or execute various example logical blocks,modules, and circuits that are described with reference to the contentdisclosed in the present disclosure. The processor may also be acombination of computing functions, for example, a combination of one ormore microprocessors or a combination of a DSP and a microprocessor.

A person skilled in the art may clearly understand that, descriptions ofthe embodiments provided in the present disclosure may be mutuallyreferenced. For ease and brevity of description, for example, forfunctions of the apparatuses and devices and performed steps that areprovided in the embodiments of the present disclosure, refer to relateddescriptions in the method embodiments of the present disclosure.

The methods or algorithm steps described with reference to the contentdisclosed in the present disclosure may be implemented in a hardwaremanner, or may be implemented in a manner of executing a softwareinstruction by a processor. The software instruction may include acorresponding software module. The software module may be stored in arandom access memory (RAM), a flash memory, a read-only memory (ROM), anerasable programmable ROM (EPROM), an electrically EPROM (EEPROM), aregister, a hard disk, a removable hard disk, a compact disc ROM(CD-ROM), or a storage medium in any other forms well-known in the art.A storage medium used as an example is coupled to the processor suchthat the processor can read information from the storage medium, and canwrite information into the storage medium. Certainly, the storage mediummay be a part of the processor. The processor and the storage medium maybe located in an ASIC. In addition, the ASIC may be located in userequipment. Certainly, the processor and the storage medium may exist inthe user equipment as discrete components.

It should be understood that, in several embodiments provided in thisapplication, the disclosed system, device, and method may be implementedin other manners without departing from the scope of this application.For example, the described embodiment is only an example. For example,the module or unit division is only logical function division and may beother division in actual implementation. For example, a plurality ofunits or components may be combined or integrated into another system,or some features may be ignored or not performed. The units described asseparate parts may or may not be physically separate, and partsdisplayed as units may or may not be physical units, may be located inone position, or may be distributed on a plurality of network units.Some or all of the modules may be selected according to actual needs toachieve the objectives of the solutions of the embodiments. A person ofordinary skill in the art may understand and implement the embodimentsof the present disclosure without creative efforts.

In addition, the schematic diagrams illustrating the system, device,method and different embodiments may be combined or integrated withother systems, modules, technologies or methods without departing fromthe scope of this application. In addition, the displayed or discussedmutual couplings or direct couplings or communication connections may beimplemented using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electrical, mechanical, or other forms.

The descriptions are only specific implementations of the presentdisclosure, but are not intended to limit the protection scope of thepresent disclosure. Any variation or replacement readily figured out bya person skilled in the art within the technical scope disclosed in thepresent disclosure shall fall within the protection scope of the presentdisclosure. Therefore, the protection scope of the present disclosureshall be subject to the protection scope of the claims.

What is claimed is:
 1. A beamforming training method, comprising:sending, by a first device, beamforming training request information toa second device, wherein the beamforming training request informationcomprises at least one of training phase information, channel numberinformation, channel bandwidth information, channel transmission modeinformation, or information about a quantity of spatial flows of atraining sequence; receiving, by the first device, configurationinformation from the second device based on the beamforming trainingrequest information; and performing, by the first device, beamformingtraining based on the configuration information.
 2. The beamformingtraining method of claim 1, wherein the beamforming training requestinformation is comprised in a service period (SP) request frame, a grantframe, or a grant acknowledgment frame.
 3. The beamforming trainingmethod of claim 1, wherein the training phase information indicates asector-level sweep (SLS) phase or a Beam Refinement Protocol (BRP)phase.
 4. The beamforming training method of claim 3, wherein thechannel bandwidth information indicates one or more channel numbers whenthe channel number information indicates that a channel with a specifiednumber is requested or when the training phase information indicates theBRP phase, and wherein the channel bandwidth information indicates achannel bandwidth when the channel number information indicates that thechannel with the specified number is not requested or when the trainingphase information indicates the SLS phase.
 5. The beamforming trainingmethod of claim 1, wherein the channel transmission mode informationindicates whether a beamforming training sequence uses a channelaggregation mode or a channel bonding mode.
 6. A beamforming trainingmethod, comprising: receiving, by a second device, beamforming trainingrequest information from a first device, wherein the beamformingtraining request information comprises at least one of training phaseinformation, channel number information, channel bandwidth information,channel transmission mode information, or information about a quantityof spatial flows of a training sequence; and allocating, by the seconddevice to the first device based on the beamforming training requestinformation, a channel for beamforming training.
 7. The beamformingtraining method of claim 6, wherein beamforming training requestinformation comprises the channel bandwidth information and either thetraining phase information or the channel number information, whereinthe training phase information indicates sector-level sweep (SLS) phaseor the channel number information in the beamforming training requestinformation indicates that a channel with a specified number is notrequested, wherein the channel bandwidth information indicates a channelbandwidth, and wherein allocating the channel for the beamformingtraining comprises allocating, by the second device to the first device,a channel whose channel bandwidth is less than or equal to the channelbandwidth indicated by the channel bandwidth information.
 8. Thebeamforming training method of claim 6, wherein the beamforming trainingrequest information comprises the channel bandwidth information andeither the training phase information or the channel number information,wherein the training phase information indicates a Beam RefinementProtocol (BRP) phase or the channel number information indicates that achannel with a specified number is requested, wherein the channelbandwidth information indicates one or more channel numbers, and whereinallocating the channel for the beamforming training comprisesallocating, by the second device to the first device, at least onechannel whose channel number is indicated by the channel bandwidthinformation.
 9. The beamforming training method of claim 8, wherein thebeamforming training request information further comprises theinformation about the quantity of the spatial flows of the trainingsequence and the training phase information, wherein the training phaseinformation indicates the BRP phase, and wherein the information aboutthe quantity of the spatial flows of the training sequence indicates aquantity of transmit spatial flows of a training field.
 10. Thebeamforming training method of claim 6, wherein the beamforming trainingrequest information comprises the channel transmission mode information,wherein the channel transmission mode information indicates whether abeamforming training sequence uses a channel aggregation mode or achannel bonding mode, and wherein allocating the channel for thebeamforming training comprises allocating, by the second device to thefirst device, a channel whose channel mode is the same as a channel modeindicated by the channel transmission mode information.
 11. Acommunications device, comprising: a memory configured to store acomputer program; and a processor coupled to the memory, wherein thecomputer program causes the processor to be configured to: send,beamforming training request information to a first device, wherein thebeamforming training request information comprises at least one oftraining phase information, channel number information, channelbandwidth information, channel transmission mode information, orinformation about a quantity of spatial flows of a training sequence;receive, configuration information from the first device based on thebeamforming training request information; and perform, beamformingtraining based on the configuration information.
 12. The communicationsdevice of claim 11, wherein the beamforming training request informationis comprised in a service period (SP) request frame, a grant frame, or agrant acknowledgment frame.
 13. The communications device of claim 11,wherein the training phase information indicates a sector-level sweep(SLS) phase or a Beam Refinement Protocol (BRP) phase.
 14. Thecommunications device of claim 13, wherein the channel bandwidthinformation indicates one or more channel numbers when the channelnumber information indicates that a channel with a specified number isrequested or when the training phase information indicates the BRPphase, and wherein the channel bandwidth information indicates a channelbandwidth when the channel number information indicates that the channelwith the specified number is not requested or when the training phaseinformation indicates the SLS phase.
 15. The communications device ofclaim 11, wherein the channel transmission mode information indicateswhether a beamforming training sequence uses a channel aggregation modeor a channel bonding mode.
 16. A communications device, comprising: amemory configured to store a computer program; and a processor coupledto the memory, wherein the computer program causes the processor to beconfigured to: receive beamforming training request information from afirst device, wherein the beamforming training request informationcomprises at least one of training phase information, channel numberinformation, channel bandwidth information, channel transmission modeinformation, or information about a quantity of spatial flows of atraining sequence; send a sector sweep frame of a responder sector sweep(RSS) to a second device; and allocate, to the first device based on thebeamforming training request information, a channel for beamformingtraining.
 17. The communications device of claim 16, wherein thebeamforming training request information comprises the channel bandwidthinformation and either the training phase information or the channelnumber information, wherein the channel bandwidth information indicatesa channel bandwidth when the training phase information indicates asector-level sweep (SLS) phase or the channel number informationindicates that a channel with a specified number is not requested, andwherein the computer program further causes the processor to beconfigured to allocate, to the first device, a channel whose channelbandwidth is less than or equal to the channel bandwidth indicated bythe channel bandwidth information.
 18. The communications device ofclaim 16, wherein the beamforming training request information comprisesthe channel bandwidth information and either the training phaseinformation or the channel number information, wherein the channelbandwidth information indicates one or more channel numbers when thetraining phase information indicates a Beam Refinement Protocol (BRP)phase or the channel number information indicates that a channel with aspecified number is requested, and wherein the computer program furthercauses the processor to be configured to allocate, to the first device,at least one channel whose channel number is indicated by the channelbandwidth information.
 19. The communications device of claim 18,wherein the beamforming training request information further comprisesthe information about the quantity of the spatial flows of the trainingsequence and the training phase information, and wherein the informationabout the quantity of the spatial flows of the training sequenceindicates a quantity of transmit spatial flows of a training field whenthe training phase information indicates the BRP phase.
 20. Thecommunications device of claim 16, wherein the beamforming trainingrequest information comprises the channel transmission mode information,wherein the channel transmission mode information indicates whether abeamforming training sequence uses a channel aggregation mode or achannel bonding mode, and wherein the computer program further causesthe processor to be configured to allocate, to the first device, achannel whose channel mode is the same as a channel mode indicated bythe channel transmission mode information.